Sight glass for industrial applications

monitoringfor vacuumfor low-pressure networks

Overview
Industrial sight glass and process observation window assemblies engineered for inspection and monitoring in high-pressure, high-temperature and corrosive process environments. Designed to allow safe, uninterrupted visual verification of reaction stages, fluid levels, phase separation and cleaning without opening vessels.

Key performance highlights

• Temperature ranges from -60°C to +600°C depending on glass material
• Pressure ratings up to 400 bar for fused safety windows
• Compatible with full vacuum service; hydrostatic testing at 1.43× design pressure

Product Categories
Fused Safety Windows
Mechanically pre-stressed sight glass with glass-to-metal fusion for maximum pressure and impact resistance.

• Borosilicate glass fused to duplex stainless steel
• Compressive pre-stress to avoid tensile failure
• High thermal shock and impact resistance
• DIN 7080 compliant pressure ratings
• Suited for critical high-pressure applications

Weld-On Sight Glass Assemblies
Permanent vessel integration via welded flanges for compact, robust installation.

• Low-profile design for confined spaces
• Available in low- and high-pressure versions
• Standard 316L stainless steel construction
• Circular and obround viewing areas
• Optional integrated lighting provisions

Bolt-On Industrial Assemblies
Flanged sight glass systems for standardized nozzle connections and removable maintenance access.

• DIN and ANSI flange compatibility
• Field-serviceable glass replacement
• Multiple diameters (DN25–DN300)
• Gasket selection for chemical compatibility
• Suitable for retrofit installations

Sanitary Hinged Windows
Hygienic hinged covers for quick access in pharmaceutical and food processing environments.

• Tri-clamp mounting per DIN 32676
• Electropolished surfaces (Ra ≤ 0.8 µm)
• Tool-free opening for inspection
• FDA-compliant materials and gaskets
• CIP/SIP compatible designs

Threaded Sight Windows
Compact screw-in observation windows for pipelines, tees and small vessel ports.

• NPT and BSP thread options
• Space-efficient installation
• Ideal for pipelines and auxiliary ports
• Fused or conventional glass options
• Rapid field replacement capability

Obround & Rectangular Windows
Extended viewing area configurations for level indication and large-scale monitoring.

• Optimal for liquid level observation
• Vertical orientation available for tank gauging
• Reinforced multi-pane construction
• Custom dimensions on request
• Flanged or weld-on mounting

Technical Specifications
Glass Materials

• Soda lime glass: -20°C to +120°C
• Borosilicate glass (Type 3.3): -60°C to +300°C
• High-temp borosilicate: up to +450°C
• Quartz glass: up to +600°C
• Sapphire (optional): ultra-high pressure/temperature capability

Metal Components & Finishes

• Standard: 316L stainless steel
• Duplex stainless for fused windows: 1.4462 / F51
• Special alloys available: Hastelloy, Inconel, Titanium
• Standard finish: 2B mill finish
• Sanitary finish: electropolished Ra ≤ 0.8 µm

Operating Parameters

• Vacuum service: full vacuum compatible
• Low pressure (standard): up to 16 bar
• High pressure (fused): up to 400 bar
• Thermal shock resistance: ΔT = 170 K (borosilicate)
• Pressure testing: hydrostatic at 1.43× design pressure

Standards & Compliance

• Pressure equipment: PED 2014/68/EU
• Glass quality: DIN 7080 / DIN 7081
• Sanitary standards: 3-A, EHEDG
• Pharmaceutical: EU GMP, FDA CFR 21
• Material certificates: EN 10204 3.1 / 3.2

Industry Applications
Suitable for chemical processing, pharmaceutical manufacturing (sterile observation, GMP), food & beverage (hygienic level monitoring), petrochemical & refining (high-pressure hydrocarbon processes), water treatment, biotechnology, specialty chemicals and renewable energy processes.

Sight Glass Selection Guide (summary)

• Operating pressure & temperature: choose fused safety windows for >16 bar or large pressure fluctuations; select glass by temperature requirement
• Mounting configuration: weld-on for permanent integration; bolt-on for replaceability; threaded for pipe ports; tri-clamp for sanitary uses
• Process media compatibility: match glass, metal and gasket materials to media
• Viewing area & optics: circular fused windows for reaction monitoring; obround/rectangular for level indication
• Hygiene & regulatory: electropolished surfaces, tri-clamp and FDA/3‑A/EHEDG compliance for pharma/food
• Hazardous areas: specify ATEX/zone and explosion-proof options where required